Elastic suspension of a wheeled vehicle

ABSTRACT

An elastic suspension of a vehicle having a frame with at least one axle includes a lamination (3) of leaf springs interposed between the frame (1) and axle (2) and mechanically connected thereto. A plate bracelike spring (4) extends lengthwise of the lamination (3) of leaf springs. The adjacent mid portions (5,6) of the lamination (3) of leaf springs and plate bracelike spring (4) are mechanically interconnected by means of a fastening assembly (7).

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to devices for absorbing dynamic loads, and moreparticularly to elastic suspensions of wheeled vehicles.

2. Description of the Prior Art

The presently widely expanding use of wheeled vehicles, as well as theirincreasing number and variety of functional designations, necessitatehigher speeds thereof in laden and unladen state, and greater net loadscarried thereby, preferably accompanied by fuel economy.

There is known an elastic suspension of a wheeled vehicle having a framewith at least one axle (cf. e.g., "The KamAZ Truck" by I. M. Jurkovskyand V. A. Tolpygin, Moscow, the DOSAAF Publishwers, 1975, p. 227)comprising a lamination of springs interposed between the frame and axleof the vehicle and mechanically connected thereto.

However, the use in this suspension of a plurality of laminated springsresults in linear resilient characteristics of the suspension, whichaffects the riding performance of the vehicle under certain road surfaceconditions.

In addition, the spring lamination includes a number spring sufficientto withstand the entire vertical load exerted on the wheels, whichresults in much metal being consumed for fabricating the suspension.

Another disadvantage of the above prior art suspension resides in thatfabrication and assembly of spring the lamination containing a pluralityof springs is labour consuming.

It is therefore an object of the present invention to provide an elasticsuspension of a wheeled vehicle capable of improving the ridingperformance of the vehicle.

Another object of the invention is to reduce the amount of metalconsumed for fabricating the elastic suspension of a wheeled vehicle.

One more object of the invention is to make fabrication and assembly ofthe elastic suspension of a wheeled vehicle less labour consuming.

SUMMARY OF THE INVENTION

The invention aims at providing an elastic suspension of a wheeledvehicle having such additional elements which would ensure apredetermined non-linear, resilient characteristic of the suspension,reduce the amount of metal consumed for its fabrication, make thefabrication less labour-consuming and simplify the assembly of thesuspension.

The aims of the invention are attained by an elastic suspension of awheeled vehicle having a frame with at least one axle comprising alamination of leaf springs interposed between the frame and axle andmechanically connected thereto. According to the invention, the elasticsuspension, additionally includes a plate brace-like spring extendinglengthwise of the leaf spring lamination, and a fastening assembly bymeans of which the springs of the leaf spring lamination and the platebrace-like spring are mechanically interconnected at their midportions.

Preferably, the fastening assembly of the elastic suspension of awheeled vehicle is mechanically linked with the axle, or in the case oftwo adjacent axles, with the frame of the vehicle, the end portions ofthe plate brace-like spring being mechanically connected to the frame orto the corresponding axles of the vehicle.

Desirably, the elastic suspension of a wheeled vehicle additionallyincludes two shackles with one end of each shackle pivotably connectedto the end of a corresponding end portion of the plate brace-like springthe other end of each such shackle being connected to the frame orcorresponding axle of the vehicle.

Advisably, the elastic suspension of a wheeled vehicle includes afastening assembly which contains three clamping elements disposed oneabove another and drawn together, the length of each clamping elementbeing smaller than the length of the midportion of the plate brace-likespring, whereas the outer surface of each extreme clamping element has alongitudinal groove, one such groove has a width corresponding to thethickness of the plate bracelike spring, the width of the otherlongitudinal groove corresponding to the width of the lamination of leafsprings, the two surfaces of the middle clamping element also havinglongitudinal grooves, the width of one such groove corresponding to thethickness of the plate brace-like spring, whereas the width of the otherlongitudinal groove corresponds to the width of the leaf springlamination, each of these latter grooves being disposed in front of thegroove of the respective extreme clamping element.

The present invention ensures the provision of a predeterminednon-linear resilient characteristic of the suspension to result inimproved riding characteristics of the vehicle.

Desirably, the elastic suspension of a wheeled vehicle according to theinvention additionally comprises two shackles with one end of each suchshackle pivotably connected to the end of the corresponding end portionof the plate brace-like spring, the other end being connected to theframe or to the corresponding axles of the vehicle.

The invention also ensures absorption of dynamic loads exerted on thevehicle to result in a wider range of functional capabilities of theelastic suspension of a wheeled vehicle.

The invention further enables to considerably reduce the number ofsprings in the leaf spring lamination, whereby the amount of metalconsumed for the fabrication of the suspension of a wheeled vehicle issubstantially reduced.

In addition, the invention requires less labour to be consumed for thefabrication of the elastic suspension of a wheeled vehicle.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Other objects and attending advantages of the invention will become morefully apparent from a more detailed description of specific embodimentsthereof taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a general view of an elastic suspension of a wheeled vehicleaccording to the invention;

FIG. 2 is a cross-section taken along the line II--II in FIG. 1;

FIG. 3 is a general view of the elastic suspension of a wheeled vehicleas shown in FIG. 1 when a static load is exerted thereon;

FIG. 4 is a view of the elastic suspension of a wheeled vehicle as shownin FIG. 1, when the maximum dynamic load is exerted thereon;

FIG. 5 is a general view of the proposed elastic suspension of a wheeledvehicle having two adjacent axles; and

FIG. 6 is a cross-section taken along the line VI--VI in FIG. 5.

BEST MODE OF CARRYING OUT THE INVENTION

An elastic suspension of a wheeled vehicle having a frame 1 (FIG. 1) andan axle 2 comprises a lamination 3 of leaf springs (two such springs inthe case under discussion), and a plate brace-like spring 4, midportions5 and 6 of these springs 3 and 4, respectively, being rigidlyinterconnected by means of a fastening assembly indicated generally at7. The fastening assembly 7 (FIGS. 1 and 2) includes clamping elements8, 9 and 10 arranged one above another and extending for a lengthsubstantially shorter than the length of the midportion 6 of the spring4. The surfaces of the elements 8 and 9 facing each other are providedwith longitudinal grooves of a width corresponding to the thickness ofthe spring 4, these grooves being adapted to receive the midportion 6 ofthe spring 4. The surfaces of the elements 9 and 10 facing each otherare also provided with longitudinal grooves of a width corresponding tothe width of the spring lamination 3, these grooves accommodating themidportion 5 of the springs 3. The element 8 overlies the axle 2. Theelements 8, 9 and 10, as well as the spring lamination 3 and spring 4are drawn together by U-bolts 11 and tightened by nuts 12. Attached toone end of the lamination of springs 3 (FIG. 1) is a lug 13 pivotablyconnected to a bracket 14, which is rigidly affixed to the frame 1. Theopposite end of the spring lamination 3 is interposed between shapedsupports 15 of a bracket 16 also rigidly affixed to the frame 1.Connected pivotably to the ends of end portions 17, 18 of the spring 4are ends of shackles 19 and 20, respectively. Other ends of the shackles19 and 20 are pivotably connected to the frame 1. The shackles 19 and 20depart to the angles α and β from the vertical, when the suspension isunloaded. Connected to the frame 1 above the fastening assembly 7 is arebound bumper 21. The wheel of the vehicle is represented by thedash-dot line. In the free state of the suspension the axis of the wheelcoincides with the lateral axis of the axle 2 levels at the line O--O.

FIG. 3 represents the elastic suspension of a vehicle shown in FIG. 1under a static load, when the shackles 19 and 20 depart from thevertical to the angles α₁ and β₁, respectively. The axis of the wheel(i.e, the lateral axis of the axle 2) levels at the line O₁ --O₁ passingat a distance f determined by the magnitude of static deflection of thespring lamination 3 and spring 4 from the line O--O.

FIG. 4 illustrates the elastic suspension of a vehicle according to FIG.1, when dynamic loads are exerted thereon and the shackles 19 and 20depart from the vertical to the angles α₂ and β₂, respectively. The axisof the wheel (i.e., the lateral axis of the axle 2) levels at the lineO₂ --O₂ passing at a distance f₂ determined by the magnitude of thedynamic deflection of the spring lamination 3 and spring 4 from the lineO--O.

According to another embodiment of the elastic suspension of a wheeledvehicle provided with two adjacent axles 22 and 23 (FIG. 5) havingspacers 24 and 25, respectively, ends of a spring lamination 16 bear onthese spacers 24 and 25. Connected to the spacers 24 and 25 are limitingstops 27 and 28. Brackets 29 and 30 are attached to the axles 22 and 23.Connected pivotably to the bracket 29 are ends of shackle 31 and rod 32,whereas connected pivotably to the bracket 30 are ends of shackle 33 androd 34. Other ends of the shackles 31 and 33 are pivotably connected tothe ends of the end portions 17, 18 of the spring 4. A bracket 36 isattached to a frame 35, whereas the rods 32 and 34 are pivotablyconnected to the bracket 36. The bracket 36 has attached thereto abalancer 37 having a shaft 38 embraced by a shoe element 39. The spring4 and the spring lamination 3, as heretofore described, as well as theshoe 39 of the balancer 37, are drawn together by the fastening assembly7 (FIG. 5). The fastening assembly 7 is fashioned as aforedescribed, butthe element 10 (FIG. 6) bears on the shoe element 39 to be clampedtogether with the springs 3, element 9, spring 4 and element 8 (arrangedone above another) by pins 40 tightened by the nuts 12. In the staticstate of the vehicle the geometrical line 41 connecting centers 42 and43 of the respective axles 22 and 23 is parallel with the plane ofmovement thereof along a smooth road surface.

The elastic suspension of a wheeled vehicle with reference to FIGS. 1,2, 3 and 4 operates in the following manner.

When unloaded, the suspension is subject only to the action of the forceof gravity of the spring lamination 3, plate brace-like spring 4,fastening assembly 7, and axle 2 (forces arising due to tightening thenuts 12 not being considered). Therewith, the deflection angles α and βof the shackles 19 and 20 are at the minimum and almost equal inmagnitude. A small difference in these angles α and β, and in the lengthof the shackles 19 and 20 is dictated by the kinematics of thesuspension. During operation the spring lamination 3 is capable of notonly pivoting about the axis of the lug 13, but also of movinglongitudinally relative to the bracket 16.

In the static state, that is under the action of the weight of the fullyladen vehicle, the springs of the spring lamination 3 straighten toalmost horizontal, whereas the plate brace-like spring 4 deforms. Themovement or deflection of the suspension equals the distance f₁, andinclination angles α and β of the shackles 19 and 20 increased to α₁ andβ₁ respectively.

Reaction Q of the road surface is balanced by the force of gravity G(FIG. 1), reactions P and P₁ (FIG. 3) of the spring lamination 3, and bythe vertical components Q₁ and Q₂ of the bearing reactions R and R₁ ofthe spring 4, the horizontal components of the reactions R and R₁ beingT and T₁, respectively.

During the dynamic, that is the maximum deflection f₁ (FIG. 4), thespring lamination 3 and the plate brace-like spring 4 deflect to theframe 1 of the vehicle until the element 10 (FIG. 3) of the fasteningassembly 7 is thrust against the rebound bumper 21. The inclinationangles α₂ (FIG. 4) and β₂ of the shackles 19 and 20 are at the maximum.Accordingly, the aforedescribed vertical loads Q, Q₁, Q₂ change to Q₃,Q₄, Q₅, and P and P₁ change to P₂ and P₃, whereas the horizontalcomponents T and T₁ of the bearing reactions R and R₁ of the spring 4exerted on the suspension change to T₂ and T₃ at the bearing reactionsR₂ and R₃ to reach the maximum values.

One feature of the proposed suspension is that when the total loadsexerted thereon vary, the bearing reactions R₂ and R₃ are changed bothin magnitude and direction.

Therefore, the stresses in the cross-sections of the plate brace-likespring 4 vary, depending on the load Q, according to non-linearparameters. Consequently, the rigidity of the proposed suspension alsochanges according to non-linear coefficients, which in turn determinesthe non-linearity of its resilient characteristics.

The elastic suspension of a vehicle having two adjacent axles 22 and 23(FIG. 5) operates substantially as heretofore described, when thevehicle moves on a smooth road.

When the vehicle moves along a road with surface irregularities or whenovercoming bumps and holes, the proposed suspension can exhibit theinherent equilibrium capacity, that is it can change the angle of thegeometrical line 41 to ensure continuous contact of the wheels with theroad surface. The wheel of the axle 22, for example, can elevate to acertain height as compared with the position thereof illustrated in FIG.5, whereas the wheel of the axle 23 can lower to approximately the samemagnitude. Therewith, the loads acting on the wheels are equalized toremain substantially equal, that is the wheels are balanced relative tothe axis 38 of the balancer 37. This is accompanied by the springlamination 26 and the brace-like spring 4 with the fastening assembly 7and shoe 39 of the balancer 37 turn as a unit relative to the axis 38 ofthe balancer 37 to the angle at which the line 41 departs from itsstatic position. Simultaneously, the rods 32 and 34 tend to pivot toangles equal in magnitude but different in sign. This position ismaintained until the line 41 returns to its static position. Thetraction and brake forces are taken up by the rods 32 and 34, as well asby the spring 4, to be therefore transmitted to the frame 35 through thebracket 36. The forces acting on the wheel in a direction perpendicularto the plane of movement of the vehicle are transmitted from thelimiting stops 27 and 28 to the side surface of the spring lamination 26to be taken up by the frame 35 through the fastening assembly 7, show 39and bracket 36.

According to the invention, the length of each clamping element 8 (FIGS.2 and 6), 9 and 10 of the fastening assembly 7 (FIGS. 1 and 3) is lessthan the length of the midportion 6 (FIGS. 1, 4, 5) of the spring 4.Accordingly, the provision of the fastening assembly 7 influences butnegligibly the deflection of the spring 4 under the action of thevertical force exerted thereon.

The invention allows simplification of the assembly of the suspension.

In addition, the invention ensures that a smaller amount of metal isrequired for fabricating the suspension, while improving the ridingperformance of the vehicle in general.

The invention can find application in any wheeled vehicle, such as car,truck, or truck trailer, where dynamic loads exerted on the wheels needabsorption.

We claim:
 1. An elastic suspension of a wheeled vehicle comprising aframe with at least one axle including a lamination of springsinterposed between the frame and axle and mechanically connectedthereto, a plate brace-like spring (4) extending lengthwise of the leafspring lamination (3), and a fastening assembly (7) by means of whichthe springs of the leaf spring lamination (3) and the plate brace-likespring (4) are mechanically interconnected at their midportions (5,6).2. A suspension as claimed in claim 1, wherein the fastening assembly(7) is mechanically linked with the axle (2), end portions (17,18) ofthe plate brace-like spring (4) being mechanically connected to theframe (1) of the vehicle.
 3. A suspension as claimed in claim 2, furthercomprising two shackles (19, 20) with one end of each such shacklepivotably connected to the end of a corresponding end portion (17, 18)of the plate brace-like spring (4), the other end of each shackle beingconnected to the frame (1) of the vehicle.
 4. A suspension as claimed inany of the claims 1-3, wherein the fastening assembly (7) contains threeclamping elements (8,9,10) disposed one above another and drawntogether, the length of each clamping element being smaller than thelength of the midportion (6) of the plate brace-like spring (4), whereasthe inner surface of each extreme clamping element (8,10) has alongitudinal groove, one such groove has a width corresponding to thethickness of the plate brace-like spring (4), the width of the otherlongitudingal groove corresponding to the width of the lamination (3) ofleaf springs, the two surfaces of the middle clamping element (9) alsohaving longitudinal grooves, the width of one such groove correspondingto the thickness of the plate brace-like spring (4), whereas the widthof the other longitudinal groove corresponds to the width of the leafspring lamination (3), each of these latter grooves being disposed infront of the groove of the respective extreme clamping element (8 and10).
 5. A suspension as claimed in claim 1, wherein at least twoadjacent axles are provided, and wherein the fastening assembly (7) ismechanically linked with the frame (35) of the vehicle, and end portions(17, 18) of the plate brace-like spring (4) are mechanically connectedto corresponding axles (22 and 23).
 6. A suspension as claimed in claim2, wherein at least two adjacent axles are provided, and furthercomprising two shackles (31, 33) with one end of each such shacklepivotally connected to the end of a corresponding end portion (17, 18)of the plate brace-like spring (4), the other end of each shackle beingconnected to the corresponding axles (22, 23).